1. Field of the Invention
The present invention relates in general to a system and a method for automatically detecting a variation of video information, and more particularly to a system and a method for automatically detecting a variation of video information, which are capable of decoding a scanned video signal from a monitoring camera, storing the decoded video signal, detecting the variation of video information on the basis of the stored video signal, displaying a portion of the video signal on a screen corresponding to the detected variation of video information, and giving an alarm in accordance with the detected variation of video information.
2. Description of the Prior Art
With reference to FIG. 1, there is shown a schematic diagram of a basic construction of a conventional monitoring system. As shown in this drawing, the conventional monitoring system comprises a monitoring camera 1 for obtaining video information with regard to a place to be monitored, and a monitor 3 for receiving the video information from the monitoring camera 1 through a cable 2 and displaying the received video information on the screen.
In the conventional monitoring system, monitoring camera 1 is installed in a place to be monitored and is connected to the monitor 3 via the cable 2. As a result, a watchman watches the monitor 3 to grasp a situation in the place to be monitored.
In the conventional monitoring system with the above-mentioned construction, however, the watchman must watch continuously the monitor 3, with great conscientiousness, to monitor the situation in the place to be monitored, without missing a moment, from beginning to end. In particular, it is extremely difficult for the watchman to watch continuously only the monitor in a difficult case such as a night-watch. In this case, the watchman sometimes cannot watch the monitor continuously and leaves his or her seat unoccupied, for a short time, in order to handle a different job. At this time, if a trespasser intrudes into the place to be monitored, or a sudden happening breaks out in that place and thereafter the situation in that place is returned to the original one, or is suspended, the watchman cannot detect the presence of the trespasser or the breaking-out of the sudden happening upon resuming his or her watching of the monitor 3. As a result, the watchman cannot perform his or her monitoring duty perfectly.